SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '460b773d9ae4b52d5b48366941b4230e368fe401d863fb28c0e385da24eefde2' 
  AND token = 'Dy/OPI2Wi6udtSTdaQoHgo31YHbOrRgcHSZdlXNUO6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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