SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89386b16825d3dd5cda52eeb7f4f08dcdff18bc4f763422acbaf586c5b3d1462' 
  AND token = 'dRUkRme9qvHrmg6KV7jE8I9XxbwSUulv9ukXr6hpimY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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