SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dc63e5f0bfd28244a833875058f102c503eb23b9bd64ac251c83055e35c1bf0' 
  AND token = 'BIjxLnT/sflX7oYxT8rK90+5V+wXJUvNJ3/Vh6/MQNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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