SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '478946c1d1ec1aef3cb09d2386e64f557d19ded43d9765470a4ae059ac45f042' 
  AND token = 'm34/rZ7Atwap2hNZSk8ePhKBixBW10rYGac4CKEjgDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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