SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '56998e076c52425121f032d754e854d67285098353051a93a1d793707dd2a9d7' 
  AND token = 'TVjF/xU6oiXACr3exj7HzQsBY2oqmR4dm//PN+9uKwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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