SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b233e655ea4350590f8643557868d867f560bbda736422f117064e59ec9aab9e' 
  AND token = 'lAKYduPHr+nzsmKmxsziL+Nvg8qRTXhVymJ6xd3p3mI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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