SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1aa532cc7b99d6ea1a6abc39dfabf86d9e2c29a37f7a0d1a4b2759725945a93b' 
  AND token = '4j4bIZlxor5s1xZbqR/yp7HGm+EeoIzZ5Fow3KvBhN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}