SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26ec0b5f874d4ba68a5663d17675e528728a02d1b098c5aecfa696f4e9ce2142' 
  AND token = 'IHVGew/J6ZVBTbOVvwLSZDMnmRJjFv+BVb0tEX/QXDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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