SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac06a844a275626fa17b001871adf0ce39dcd63bcb40eb3bf26e2d502779fe7e' 
  AND token = 'dcc3bwXffjqBY4fxYv9uPphoThM+gZDhBXKjmQMg7BE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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