SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a709c1541cd5998f5311fb6f84572866a8d346a9d1fc2114bb9e5f756a0348bb' 
  AND token = 'przRKQIDDvylPZYhSqiDOJ66b8p0VShjJfx+OWigk14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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