SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ad4f0370971a74ae45518bac19b9214cbdccf1a7f64f33d75219ec3e9710826' 
  AND token = '1kjnHn33nmTzxdrd+qvWwlTwYQFi/fWnBuF1bGNvxoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}