SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '325c1b49559306846b7f7b115e9f50a2cce7a2b98d1791864f80ab6881ccb6bb' 
  AND token = '2amM6zcjNmLKIL+/amHABfQtZTUOm8KLzg2VO1XZveA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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