SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bfbc722809fe7722b1da7e1b686e242e45d5c454b215ed28a619d302c830a25' 
  AND token = 'MHxCAvzF4DV9AKdzQxMiEAuWnAH4dWYWUqnDakAXkH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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