SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76659eb4a92e06c77ee64716a87b60191b40078e88ea896c8c39e134be80947e' 
  AND token = 'u+pEdUv54iyZwCyUOvBIb0a61y3xKRlvjwSgemKbzkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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