SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '253a97f1f86c054ff9ae44f9498a21d7f1b973c1849cc0979b382f3fa16d78ed' 
  AND token = '4UCWEQ+XCBjkAHMzgBwfTzF3pBCqPnSWmYRCEWFs2aQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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