SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7ebe2aa2d7fb4958d9ba471b93bc38226c5e87120c02a3203d2691161124ea2' 
  AND token = 'rNUxbQ4pg44d8K6U+gC4FAkScMEk+rjK95zW/IEhQ1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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