SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89f26274230c4bc6adcdba1eba1e3cb4aab528412eaae5d69fce4c36c1ca4d00' 
  AND token = 'BVQLSkQPFk5CAsffslbVIJwnDHMdN5HEGYrfTbaCmJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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