SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '008788451abea743bf7eeadd9ee936210fea1e007f0592a3de983334b2b270c3' 
  AND token = '0ogrkV0uL5HGKf94JV9SQ2iKXeAXO8H4EjBnCkxV0H0=' 
  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"
    }
  }
}