SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34cf57479fcf99175f79b9410d2723c23931cd16f94aff1a4686336aec5f253c' 
  AND token = 'AsuS7XJYQ5a0U76Y/U0pLpCioTiXxecvFZuCBmvPSKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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