SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9be88514221cd79faf18eb24675f950936f499c12cf9e4fd7572bf330eca7377' 
  AND token = 'i9aQlFpxTZ074BuGLKJnPULqwCD3va7D/Z22tAM11WU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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