SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0d4637708c75a0881aa97ddf14e0b9a418857701c39741c031651135b463b3e' 
  AND token = 'YQ491C2muRA9RM5R2cAUtshYX6YOA0zXDhw5tMzxxs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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