SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '601184a2c92a81752761c483d23abb500662f4b4e16cb429f13425f3b1418f77' 
  AND token = 'rkVKpirOF6s9SfK9bBMKzsEKWIk49q2soxNCppP9maE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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