SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '700bd77b150f878bf4507942eda86797e89c8672b4397030600f47045326b245' 
  AND token = 'xAhuLIVshsHH/W3kP2aJWZfw/YBsvn2sUy7YUG04sFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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