SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a66fc5d6fff8389d21c8b0803db16d559bd31115fd897f7888450c1ece63a934' 
  AND token = 'HH12fykKasKwQh/u//dCNptFQvwffsT8+SgFGiS0kPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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