SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f84e36a8d2c3eb42f31a5f5c47405bf206c72ff91c92ad5ad6b813fcb1bdbdd' 
  AND token = 'V8xYiIAZl7DKqOGuDrE4KUYXz85y3NLYcKTN2GUlvmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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