SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4351789e2627066e094ab444748f4bca1b45da0ca8cb7ff17584836fa4011479' 
  AND token = 'D/+HMwLpyDK0FLKEec45zLb8CVuhEPGbJdwXsoHQHHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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