SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43f239916abd2a3a0a636080d02427f045b63039984a38ee430ee485e76bdf06' 
  AND token = '6aPzeRRmPUjX/UOPipHu8IdJKfykIs+69TxJcK0pNdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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