SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b09e20f2f0cbbec816841c25eb14804f7844952e380f8773c80e2a71262ca72c' 
  AND token = 'Ku0h3hwQIi0NbZUlP2StgWhsw7/bvzxX5VW0H5cuUyw=' 
  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"
    }
  }
}