SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3301b768bd961740d560b2c5fcabad963753e25f14fcea7779bc0d8df4c97d63' 
  AND token = 'VfoyvJOIg4OorAF0jbH3pFj1jTNytVtMyndCoG7ivi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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