SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11691d8eb9d8282db3a068009c94aa8dceef3d6bd872ffe6e48df6056427ef73' 
  AND token = 'nJhPAhCjXv/Yr0gvHxyXVWvcHZnawT5H2s9jctL458A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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