SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13b7276eaa3a7ee015808ec6435bf86848166ef8639605460a786d4d23f56617' 
  AND token = 'zoUGZGwJLdQwDGUJ8R4qhojZe1GdQl2oyxzyZlQsDIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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