SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef778921d58f695bb01fb11d569ce4899b107d82a371325bafdb6073b517d535' 
  AND token = 'G9BhxlhacFfftQKYlUbgW0T2Xpyw9VDq1kf4hvYht5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}