SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a0ae5594634421f7dd5a764c9f3d28bad762c3bf3608b91f009ab24df141bbe' 
  AND token = 'C6qJ9C5WG/qbZU3dyCwAReh60ZOw8TJE1r2YOmOvjxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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