SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a99490f946027a2a260137ae49522cb76ec138c939333763ad3dd92dfe14d3a' 
  AND token = 'ulOPu0q12kRdW/WVa6OuSR17jq8l3gq4nGZ1MT/bhxI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}