SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70d45b98ffd6de0b6395143f2097da64adecb211cad486a81f95bb005a914d6a' 
  AND token = 'TXRKJUVh46R0awXaKyMbNa0ibVtAUigcqpBi+NX6Lnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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