SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bb9c7a9d8d09681fa7472145e4f81aade3f490c4d439e38871dd98763de654c' 
  AND token = 'Ttsn62ojmHVNzWyZWfOu3+y2Hgkav8DDU8z2zFl3gQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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