SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f7ea23e1c48da72fed1b060132ae94d66023685c8b8fb99c46a3a192ddb9092' 
  AND token = 'r9dqqrOobkC5j70z3AlbjPvjtr8OyvX9R0xP3KmZBEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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