SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adddf09eb26e21428ce3a2571192588dd9fbcbcbbaa31f7d6ad17187fc68e52c' 
  AND token = 'EUickCC+6pXyd/TTz6sXihi694PGQph39rHhEZuln3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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