SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6242c18162e99c6766ec17882df5cf481626cb15bf509d1dda518d27a1e120dd' 
  AND token = 'VomU09t7drU19rqx3QC923tWTxHxknSkf5w0Cqo31qs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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