SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24bcd4af90c57f1b24e700c1a34c3e88765e9906f943f679f55573a890696e15' 
  AND token = 'jjIkjLnWq0FFq79bWh3IfSVMK69u9cyAY2MvFo0+Lhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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