SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1da3f1d2aff6729418dbdabdda0683717afb15177ddc377d9846903fb26c93a1' 
  AND token = 'BijsMeXFWtbMfoEAiB1/eA8VjEx+xYajt4BG4EdCdEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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