SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '078c3050f957273e343d1d7b7d87115c9a98f44d348ea854f634086322284542' 
  AND token = 'jxDawXNGyXVMtBduOrsUa+5kQf49DskWkXHLp+tYv34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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