SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '742292f0640b25c982b43f531b427e05850ab0f2608c1a5f736e9bcb13ea9fcf' 
  AND token = 'YUsKkliLnoEWjJkGdPE2cjz8neEEHyixWH52m4UizZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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