SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '036310e74a078bdb811c94b4eedae3673b12ae2dcbf06ab0c17fa67cec65fbad' 
  AND token = 'YqnTkTiU02zhEeMOPiDRqDrtpi5V71EukFqpG65lP8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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