SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e7ec696857b630260aa7ac9ce0e3c4daf3ba306afafe52ebd45476de14d4b18b' 
  AND token = 'F0GhiP/pe6xfLnVz8HhEZnOQSgOhMZKdgKbcMKQDtwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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