SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '232856b9599efd62fff9cd067c865e0762b1243fae1d39da2c3384186127bb6b' 
  AND token = 'ic1DEDsWo7zEN5zgaxkgS/PIIyxNQ7bbJ6THUlVknOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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