SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '736012fcd21b551e928b85fd97aafc7fd33280c0c5e3cdc95277cdb8b27f7694' 
  AND token = 'w3QrwLmIBZmUcqwWlHxDUyv+2rKWlolukbmwOe5VjM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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