SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f554edec1b2a949a8c89917786078c2f9b6cae2afb048c805003ce52479e37ea' 
  AND token = '9tBNx+G8cEA2ecz33aXEDR2vXFLjhFKWSIUSupRnWoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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