SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f3e0fd19e412541e825bab7e83cd85b393e96a60b187f8dc19aa7739aa223c0' 
  AND token = 'KWvlL/RXEdAxco7v7Jzr53dug6bzc4U/UHLRWvqdvvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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