SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e13293ef82660f77b64961dc980d65ea219185afb00b7856e4cbb5acb34ea473' 
  AND token = 'V99RTT58+EpEZgPam8KjVGKQC1oSObElpkMBmOKq6ag=' 
  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"
    }
  }
}