SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cba0f0114fb99f9514dc0e8c89377364f475ad9d4b2f275cd7fe057d119dbbd' 
  AND token = 'hcNkKyLbC7OivpBV2bEJrKq8PaCJn1bdilTzzh7Lnss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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