SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03eb8fe2952d4d0ee1dbb2a039445bb3eda802076506c132c1c03c1e51db7b60' 
  AND token = 'TCdBPmDxnGEAoLlfCxqycKjgM3znoSF5rJBtu6wUrPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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