SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0a87b4d6421a59484d032c1ab2047dc6913b4b061851ee904986a480e8c72db' 
  AND token = 'mZxxt8U/k7HTd3gkULwMFQxnS8Mw2Bfj0Mra3fvPcVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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