SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2acc1316b018cf7cc5d1bc837d83761a8563b1131a5a6819f5efe98dc9b757b5' 
  AND token = 'A/hwY7UKJLY5IYgEqLU6hjiWTntPr/cBLqAGk/4zajU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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