SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df08b4947ca84c985aa5be5b335304afdaa8ae5ac7304cf8889314404f9242bf' 
  AND token = 'p+utBFemhR3hcs4f3jXTYLLApVBbw0Q4J3Q+VbMrghk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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