SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2911b56ff0c6373d7d3c2ae9e3c4ed3e43637f4b2602136459e5c675578c8dab' 
  AND token = 'QtRemE++6t7rlqV+iGnz6jDmmB2+Aje5Y5azM/vtcKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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