SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6137105c919f27c6973d48acf2a6271d20081b9015b6d58735453b8ac852aefa' 
  AND token = 'AGd+VYduURp+9BTE5IRya6A3LYyP4uacEBwAp8MgUqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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