SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7cac5d1327a9d52c0f25bb8d2f34fc2636b654c281d224f558a904380014bfe' 
  AND token = 'Ct+o7RtKhe3CZuhoRrJGIJgjfdF9CE0nheNPcArILn8=' 
  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"
    }
  }
}