SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0816773e535e325b56c0d5c83f565c7528a800483debd8864a96b5dd1385f2d7' 
  AND token = 'zHpu20JjunKaVy16ACAIEdh85ACE2jt/MLa7rhkL5QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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