SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '964d00ce51f8247abaf6e0d2ac9f233a4b79978c3409849300b1ac5a7988f6df' 
  AND token = '0HugsrYMxewLijiafEjilmmA5EomCICDwcwuNmCpPlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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