SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8c0bc6cb429b0f2f07f0913573dd3a419302fe1a4cc6d72eaeb12c083af8714a' 
  AND token = 'd7CMvVNpf7i86b/A6RoJ1KmFKRWVAzd46rVCiKX1WZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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