SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0912a2abbf426e15d7d9f2b1e7d01ca3693f032d3650341c9798143a8a269786' 
  AND token = 'AGkfdpSsXfXHBKFTH7LlVzpjwYpJHwX5LHGQ7F14UYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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