SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac2a822a5e14089448270faa000dc0d40e06c0679be96e43d8acefc727b9caee' 
  AND token = 'b9Q/wkK+Fv4GwzsKqTV6rpzrv1YccoSodpsqQnz0Oms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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