SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b14668d9fae3f3c80bb30b3a1f59d15b16b7ae5d1094db6fb107658d00f2c0e' 
  AND token = 'EPqWlMOpuZMCssrmvH8PwyK22QhUmiApYaLgUQmMiEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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