SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c77955350488edec35cf843e0996ac841cfcb96eb7e55ff260422e5a589ec5d1' 
  AND token = 'KiLk/mtqPTh1yUhota3kaY/Z3ByqWDyw6c3oZZyqfvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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