SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd90116cf14791ea95752d1cfa2ed6f3b1c9c4f49be753049fd690f28b05940c8' 
  AND token = '6tDO90ga8JU2ycTXwbohfJrbH7nQfUdXOSFM0u07rDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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