SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48211b9ee093b1aa088ae40f7526444b24c86ee6b0dc7693ed7939b4f89e58ef' 
  AND token = 't1/7Q9nNz1HE/k26/uneTBb5Rjj72v8sSu1F9ABI9gI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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