SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cffa58034ca3690c82164705427826a80d4228a93036c8fcf1ff6523dfdd853' 
  AND token = 'MrCHrMC/NWJKUgxGhr8Ywv7Zgt8IO8m9zVAq/ml6IYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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