SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e70457cca6bd9569b08a3308d0c2222f51d8c93a425e544e5d51f72bc61a38bc' 
  AND token = '8tzoQyR9+GphUx5DBRBh4BhOjfFAmSlsAoEnT3qZ5ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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