SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '993708c54589ab739f4260c14619d7f883f973bcc712c3f246cb085d3c65ba09' 
  AND token = 'NEsq3n8wIxd05z9BFxlmBew882uQfYJqQP/dQcKeRUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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