SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9daf8ef4fb5c921e05cfbe6251f8eeb295d82f33f620edb092791a75d41e7d8' 
  AND token = 'C3i84w2UZVLrq+78ihihBfKulnhBkAxgwFodjQWMRtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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