SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64b8f3e06e87b95c5fb655ab227b2bfd233043e9582864a810c9c4b71f1410da' 
  AND token = '/xxI2h9hIQPbZAhjFfTV/Z5QoWCJEqsdHr3HHK6LG4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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