SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8e1677169d355354cc8d4fe9f135b6de5631ffea5bbdd4db479c379c6330811' 
  AND token = 'T7qSh9Ne89WZDTs8+RarT5HZtRzBDYr0y3HTB+u2wzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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