SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff0fc514e132d390afc5fb5e5e053e4aff1dfa3ac4b4bf79c3069db199d72298' 
  AND token = 'SroFW1wYTwo9rMZIa4Y8DINW6HkLdNcPf+uRCv9eqpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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