SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44f4681d98d9fd119916cfbda8b907458feda6e76fa4922987fafc249da7ce87' 
  AND token = 'Q6djEoN0QBFNjiNATyRYV0GtDI1AjxelG/bb7mBGQ2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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