SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e21deeb71fe69356ecfec9fb506ae7f0f8ec72655410e916efc6918da3405976' 
  AND token = 'GJPpGcJYr0H/2PdsGjTgNcGC3gPhoLw13YeMNUpkuoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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