SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f01308df8bf7b76c56be13f7a1233996a47707697ca1442d80495e63f1a1794' 
  AND token = 'OpjXKIj8ISg2GQW1EVwmJ4OAgd1q5XV0WQHRiMq3wzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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