SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '64a5fce854c2305d658a1aae046215173e94d86a0a724b3f35cf0f864d549209' 
  AND token = 'A6GUEIFD6li7WwX+2hjA6fQ3XBR/pKL0s9ERHJGbv20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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