SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16eb13c588b0960ad12c23f74dbe3c698f2852c2f58126fa0d7f0225200512fb' 
  AND token = 'FMG5E+lFr6vouuO9mMLbtKVPFf9PtWFpI69J7v0Imdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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