SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec8531f2d8fffef0b50a576f8e805dc965e7943f0d86152fd5287fdf022527e0' 
  AND token = 'q5ST/a7husOVosZ8HJc6d6yXMJluVIepm8krNSP1Mq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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