SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ae314d5b4fb630884909b75e9b9b011d0df355e0575ac4f97352ff28b550c85' 
  AND token = 'fGxeSodGvcY0GVymqXOTHNwm7Ft+oiUodD2BunK9MTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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