SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff95369d88dbdaa70e885af9f3a609eab7e333ed88f49983ff8fcf1b0fd6221d' 
  AND token = 'Ulq9DbKOqAfFFaDc1FKxqibs6tWImUpPyLRbA8SSeEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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