SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63a705d77c48b93f764cd0f4ac8755ec291dde50ca9076c80a827b7c7b22b596' 
  AND token = 'Omp7GmB0jTC1ypgrVnxiJYn6ItEP/DOuI+hq6x6j3TQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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