SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b79b514f40d98fdda36b455b08917463bc6aad52548f27ff89e7b1c0166b3417' 
  AND token = 'SqIKsh5zMAxK+h9QC6vUam/00HlSooqH3GXOrI3cI+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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