SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67fc39a17ffd6e5dbde6c3c93c88d74e7e2c4065f3a3c4cf10870f0c112625af' 
  AND token = 'bqXxz7aoBh08rmzg7v2rg5Deg6jGmVtl0owQ/P+r4zA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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