SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96d309a4e10ec9d6982f48400561692f3b57ab470aaa3e0232323a14ada6b35d' 
  AND token = 'P6G5ENKXIFc+are0g+CFh5CPSCNo4eN4h2rEMRh+lj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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