SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fd2a0784204e089baa64386667fbaadfc71926e414cab9ef8d4053698cd1f6e' 
  AND token = 'AvQdzxuTBUPBXH5HFs9HYy/nUdM5lw7yTerGQ1bFhd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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