SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ae622b87f90802c34ca08a9b7b28a81482c77740a8931a0a66d0202944746a4' 
  AND token = 'XGs7UqFWeWWTaf6d5JRqGZsTOr+v533cfBnoyRDy5vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}