SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fede5b740d9fa46979133c527131e7de0e72a9a669d0de86f93ff182c332b49b' 
  AND token = 'NCC/+55L8mCydnfiVh0Uan57/gtYCOH3fX8Tcuhq8ws=' 
  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"
    }
  }
}