SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1f63604611a951c9cf4bb87728391361a41d534bb6bd983748714385ab5afce' 
  AND token = 'M5/9meh7o0JM4vpzquiFPPVbEl6NRXEcVdV1vQYgzss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}