SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f1b5055031fe53bfac640fbc125dc27de6a00b367896ba9279386c7b5f7d41d' 
  AND token = 'uJlO/LLQn21ggPSoEGGPLGKcZbCIiqdnxuan1CTOLf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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