SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '524cb8a340d8c9309eeb340bd5db1914d7d0d0a47f7e0152e2748dbe61a8581e' 
  AND token = 'NpGmOj6XjD9SRce/PAvu3ZIRPe6/Y5tQaf4Y5TBMSSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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