SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f69a02dd421b109e103f9831be7e4af4eb8ffea6a9070f368399a78acd85f568' 
  AND token = 'lY9VG8Vz9QJii2hZK4ZSWYxwyjEQWxAbknzQZyvY/UQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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