SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'decdb5c87f98c0ac375e715fdb5fd8ce78865099bc171e25ee7004f6195ee819' 
  AND token = 'K1rOWHngUPHQucAQb1goFF+KfaJC4xRAVMUwJYsbyaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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