SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1e425570113192e56db296ca3848abc52af409b45cd51d054b1f8cf837fb0c4' 
  AND token = 'rGFvBsC0R+JiKTOdZ+Zz+IudcOedlvpKtjFipsdzrbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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