SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4001753fc5066c07309d28b7248a587e21f29b302dc49fcd249e0b2ec4ba744e' 
  AND token = 'p7LMJl/AgwjhlNPnmiZBxe+l2F2YvzSJM0pgIEqCjEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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