SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59f451e5199b5c2bff678da8cbd07e3f393d196375cecd6117daf5733567e2d8' 
  AND token = '0FBnyazXnoTLU3NkQszCiTAa2tMotsw7XCpzURrmVJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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