SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e351834c13ecba0cdfcaa4d1406a88c701833e09f98fde22853ea65dcc61b54' 
  AND token = 'CGEKngjcR19zQPwu/33ZMf1zGKpArXvttaNNDr1vz94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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