SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cd654ceca84fc1c529e3efe6e58f5fde3cdfb13d6afb9241757556d9db3954f' 
  AND token = 'bb9x/iIOfQTZpE99qIHFV/dVkbbC3ncnoFuKWIvT/Dk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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