SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b161b6de3bef42e98499b09760d1559d319805c4fda24e325ef233bb931c70' 
  AND token = 'bBoqgqTbhIC5MfrOVyHIgpruz1xulUehloRx0Bmi7RY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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