SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a91bc0d9b4d86182d6399a0692ed8a86905893b755ebb4ee6700b110793e2799' 
  AND token = 'tM9GFfXVjr9Tx1vdH4fsDdzbrlVXDW7gGuLsAmQg4pA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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